It's a plug and play unit. I update your old one my installing a new circuit board into your old case and use the connector.
Some advantages of mine:
1) You can program the idle RPM via a switch. 775 to 1000 RPM in 25 RPM steps.
2) Crystal controlled so the RPM you program is exactly the the RPM you get.
3) Saves power. I shut down the idle motor power if the engine is not running. And I shut down the power above 1300 RPM. This is when the idle motor is fully closed.
4) You can remove your idle switch if you desire. If you do this you must remove the diode (bypass it) in the harness near the idle ECU. Then I control your advance solenoid.
5) You can program the unit delay. This is for help with idle hunting or the user with the Volvo idle motor. With my car using the stock idle motor I have no delay programmed. I think my ECU will help with cold start hunting but hunting caused by the lambda ECU will probably not be curred.
6) I have a test mode you can enable to test your idle motor. You set this mode and it opens and shuts your idle motor slowly. You then look into the idle motor and see if the valve is sticking in any position.
7) There is an LED on the board that lights when the idle motor is fully closed. This is to help you trouble shooting an idle problem and setting your curb idle.
An air conditioning idle speed bump can be wired onto the board. This will bump the selected idle speed up 100 RPM if that signal is +12 volts.
See instructions on my web site that are in progress (still editing them).